There are numerous dental problems that arise from improper use of jaw musculature. One of these is clenching, a condition in which a patient constantly or excessively presses his or her teeth against each other. Clenching can cause excessive wear of the teeth, headaches, and fatigue and soreness of the jaw muscles.
There are at least three schools of thought on the treatment of clenching. One traditional treatment involves placing a protective layer of acrylic material (called a splint) over the involved teeth. This acrylic layer serves to protect the teeth from direct contact, thus reducing wear, and to spread the load caused by clenching so that it is shared more equally among the neighboring teeth. This reduces wear of the teeth, but the acrylic protective layer does not address the problem of clenching, which frequently continues indefinitely. This forces the patient to wear the splint indefinitely. In some cases the urge to clench is worsened.
A second traditional treatment for clenching is occlusal adjustment. This treatment involves selective grinding of teeth so that the load on the teeth caused by clenching is carried evenly by several teeth rather than being concentrated on one or two. This technique is successful with some but not all types of clenching. However, if not carefully practiced, it can lead to subsequent legal liability which is enhanced because of the permanent nature of the procedure.
A third school of thought is that there is nothing that can be done about clenching. This approach may have heretofore had the advantage of candor, but it left patients with unnecessary discomfort. Muscle relaxants are often prescribed in these instances. This group of drugs may adversely effect performance, and therefore can only be used when the patient is at home.
A second class of dental problems relates to what are termed problems in the vertical frame of reference. Examples of these problems are: (1) Dental open bite which is characterized by contact between the posterior teeth without contact between the front teeth when the jaw is closed; (2) skeletal open bite which is characterized by a sloping mandibular plane and a long face; and (3) skeletal deep bite which is characterized by short faces and mandibular planes that are nearly horizontal or parallel with the floor. Skeletal deep bite patients also have dental deep bite which is characterized by excessive overlap of the front teeth. Treatments for problems of this type are discussed below.
One method of treating a dental open bite is to mount ceramic magnets on the rearmost molars with like poles facing each other so that the molars are slowly forced more deeply into the bone which supports them. A disadvantage to this method is that the magnets and their acrylic housing force the jaw open 5-6 millimeters in the rear and perhaps twice that at the front. This imposes the responsibility upon the patient to walk around with his or her mouth open, which is embarrassing and uncomfortable. Patients also have difficulty keeping their jaws in such a position that the repelling magnets are directly opposing one another. Thus, there is a tendency for the lower jaw to slide from side to side and not to stay centered. As a result, these patients are frequently asked to wear a chin strap headgear apparatus to center the lower jaw. This method of treating open bites is prone to the problem of lack of patient cooperation.
Another method for treating dental open bites is to place a cage directly behind the upper or lower front teeth. This appliance restrains the tongue from coming forward where it has forced the front teeth apart. The patient is instructed to keep the tongue behind the cage without touching it, and whenever he or she feels their tongue touching the cage to move the tongue backward, away from the cage. The problem with this appliance is that patients forget to remind themselves to move their tongues backward and rest their tongues against the cage. When the appliance comes off, the tongue frequently comes forward to rest against the front teeth. Relapses will inevitably occur.
When dental open bites are present in patients in their teens, or later as an adult, the treatments for dental open bite are orthondontic treatment in combination with extractions of permanent teeth, or orthodontic treatment in combination with surgery, which usually includes extraction of permanent teeth.
Skeletal open bites are traditionally treated by orthodontics that includes extracting teeth and using orthopedic force in the form of headgear which imposes an intrusive force to the maxilla and maxillary teeth. Extractions help to solve the problem in a minor way and require the removal of four perfectly good teeth. The successful use of headgear is dependent upon the cooperation of the patient. The headgear includes a brace that circumscribes the head and neck, and it is cumbersome and uncomfortable. Experience has shown that cooperation in wearing the headgear is often less than complete. The use of extractions and headgear treat only the symptoms of skeletal open bites. The underlying cause of the problem which is the lack of sustained contact between the teeth is not addressed by this treatment.
Dental and skeletal deep bite are treated with orthondontic treatment which often includes propping the front teeth open with an acrylic bite plane. This leaves the posterior teeth apart and allows them to erupt into contact with each other. In the short run this treatment appears to be stable, but after about a year the deep bite may begin to return because the underlying cause of the problem (chronic clenching of teeth) was never addressed.
Another class of dental problems relates to what is termed problems in the horizontal frame of reference. Mandibular retrognathia is one such problem. It is characterized by the lower jaw being positioned too far behind the upper jaw in the horizontal frame of reference. This condition is conventionally treated with bulky acrylic appliances which hold the lower jaw forward and restrain the lower jaw from moving backward. These appliances have been shown to create undesirable side effects related to this restraint such as proclination of the lower anterior teeth. Other treatments have been: Orthodontics that usually includes extraction of teeth, or orthodontics that utilize orthopedic forces to push the upper jaw backward to meet the lower jaw. If the problem of mandibular retrognathia has not been treated by 12 to 14 years of age, it is often necessary to treat the problem with orthodontics in combination with surgery that is designed to bring the lower jaw forward.